Method of and apparatus for applying to and withdrawing liquid cleaning and treating means from textile floor covering especially carpeting



em. 29, W70 E. NOHL 3,536,517

METHOD OF AND APPARATUS FOR APPLYING TO AND WITHDRAWING LIQUID CLEANING AND TREATING MEANS FROM TEXTILE FLOOR COVERING ESPECIALLY CARPETING Filed Sept. 11, 1967 lnvenfor:

"United States Patent M 3,530,517 METHOD OF AND APPARATUS FOR APPLYING TO AND WITHDRAWING LIQUID CLEANING AND TREATING MEANS FROM TEXTILE FLOOR COVERING ESPECIALLY CARPETING Egon Nohl, 34 Raugasse, A-2700 Wiener Neustadt, Austria Filed Sept. 11, 1967, Ser. No. 666,621 Claims priority, application Austria, Sept. 12, 1966, A 8,562/66 Int. Cl. A471 11/34 US. Cl. 8-158 6 Claims ABSTRACT OF THE DISCLOSURE Cleaning of textile floor covering as, for instance, carpeting, and is characterized primarily in that cleaning liquid together with air is due to a suction effect drawn through a perforated or porous body located in a treatment head whereby at the bottom side of said perforated or porous body a foam is formed which is applied to the floor covering to be treated, said suction effect simultaneously being eifective to withdrawn the foam applied to said carpeting.

The present invention concerns the wet cleaning of surfaces, especially of textile floor covering, and in particular concerns such methods according to which after applying the liquid, the same has to be again withdrawn.

For wet cleaning of carpeting, depending on the nap weight and the nap material per square meter, approximately from 0.5 to 2.5 quarts of cleaning fluid are required. After withdrawal of the applied cleaning liquid, there remains in the nap approximately from 10 to 20% of the quantity applied of the liquid, depending on the processing type. This quantity can be reduced when the liquid is applied in a more or less prefoamed condition. The degree of wetting and the consumption of liquid can be considerably lowered in this way. Moreover, by means of the prefoamed liquid a more uniform distribution can be realized in the textile material which in turn brings about a considerably improved cleaning effect.

A heretofore known way of realizing this goal consists in employing air under pressure or pressing the liquid through porous bodies in order to produce foam which is then applied to the carpet. This liquid is after it has been correspondingly worked into the carpet, again withdrawn from the latter after a shorter or longer period of action. This method has considerable drawbacks. On one hand, the device for producing compressed air which is separate from the suction device and the feeding of compressed air to the textile fabric to be cleaned requires additional equipment, and on the other hand the foam must be rather stable in order that it will not be destroyed too fast under the influence of the suction vacuum. It is for this reason that the application of many solvents which are extremely effective for cleaning purposes is not possible because the stability of the foam will be considerably reduced when adding such solvents to be cleaning liquid. Moreover, it is necessary to connect the feeding line for the compressed air somehow with the fluid containing vessel so that the employment of different containers with different cleaning liquids is made more difficult.

It is, therefore, an object of the present invention to provide a method of an apparatus for applying and withdrawing liquid cleaning and treating means which will overcome the above mentioned drawbacks.

It is also an object of the present invention to provide 3,530,517 Patented Sept. 29, 1970 a method as set forth above, according to which no additional or separate devices will be necessary for creating the foam.

These and other objects and advantages of the invention will appear more clearly from the following specilfication in connection with the accompanying drawing diagrammatically illustrating an apparatus according to the present invention.

The method according to the present invention is characterized primarily in that the foam is produced by the vacuum effect from the liquid and is applied to the material to be treated. The method according to the invention is based on the finding that for the formation of foam it is merely necessary on a foaming element to create a pressure drop while it is irrelevant for the foam formation whether foam bubbles are produced which contain gas under a pressure higher than the normal atmospheric pressure, or whether said bubbles contain gas under normal pressure and the overpressure exists with regard to a vacuum outer atmosphere.

Taking advantage of the last mentioned possibility, the present invention employs the vacuum created for withdrawing the foam also for producing the foam. A preferred Way of producing the foam in this manner consists in that the liquid to be foamed as well as the air are withdrawn through a suitable screen body or porous body. It is from this body that the liquid comes out in the form of foam while permeated with air, and the foam passes to the surface to be treated and after a shorter or longer period of action is again withdrawn by suction air flow which produces the vacuum. The foam development may be controlled by a suitable selection of the screen body or porous body, by selecting the respective cleaning medium and by controlling the quantity which is fed per second.

According to a further development of the present invention, the development of the foam as to quantity and quality and thereby also the period during which the foam is active, as well as the depth to which the foam enters the material to be cleaned can be controlled in a simple manner by varying the strength and/or the direction of a suction air flow from the exit range or the place where the foam is created. Foam which contains a considerable amount of air (dry foam) will be more stable and penetrates less deeply into the material to be cleaned and vice versa.

The cleaning effect can be considerably improved by heating up the liquid and/or the air which is drawn by the liquid through the porous body.

According to a further development of the invention, the feeding of the liquid is interrupted after completed application of the liquid, and the treated surface is dried preferably by means of heated air which during the application passes through the porous body. The time until the flooring being treated can again be used will in this way be considerably reduced and/or the preceding degree of humidification can be increased.

The present invention also concerns an apparatus for carrying out the method of applying and withdrawing liquid cleaning andtreating means, said apparatus comprising a treatment head which is movable over the surface to be treated. In that portion of said treatment head which in the form of a bell is located immediately over the surface to be treated, there are provided means for applying liquid while the inner chamber of the bell, for purposes of withdrawing the applied liquid, is connected to a low pressure producing device. The apparatus according to the invention is characterized primarily in that in the bell there is provided a hole-slot or a porous body which on one side is exposed to the vacuum effect in the bell while the other side receives air and liquid,

preferably at normal atmospheric pressure. The apparatus according to the invention may be so designed that an air inflow pipe is inserted in the wall of the bell which pipe is open at its lower end which extends into the bell chamber and is designed as holding means for a foaming body, such as a screen or porous body. The treating liquid is conveyed to said body from the top, preferably through a pipe coaxially extending through the air inflow pipe.

According to a further development of the invention, the air inflow pipe has arranged therein an element, as for instance a slotted diaphragm or the like, for varying the cross section of the passage. Furthermore, for heating up the incoming air, a heating body is arranged in the air inflow passage. Also in the feeding line of the liquid, a heating body may be provided. In order to be able, after completed application, to continue the treatment with hot air alone for purposes of drying the article which has been cleaned, a shutoff valve may be arranged in the feeding line for the liquid. In order in this connection to avoid the throttling of the air flow by the porous body, it is possible according to the invention to move the porous body out of the postflow passage for the air.

Interposed in the path which leads through the porous body into the bell chamber and from there to the suction connection, is one or a plurality of walls which can be lifted or lowered in the manner of a gate. By means of said walls it is possible to control the intensity and the direction of the suction air flow. This is of considerable importance for the type of foam development and the application of the foam.

As will be evident from the drawing diagrammatically illustrating an apparatus according to the present invention, the bell-shaped head 1 which rests on the floor in an air-tight manner as far as possible has a withdrawing connection 2 by means of which the head is connected for instance to the suction side of a vacuum cleaner. Inserted into the wall of head 1 is an air inflow pipe 3 the lower end of which is closed with the exception of an exit slot 4 and in which a porous body 5 is arranged. This porous body receives from the top cleaning liquid through a further pipe 6 which extends through the air inflow pipe 3. The said pipe 6 may have arranged therein heating elements for heating the liquid being fed into the device. For heating the incoming air, the upper range of pipe 3 has inserted therein a heating element 7. In order to be able to vary and control the incoming quantity of air, the upper end of pipe 3 has provided therein a slotted diaphragm *8 or the like. Furthermore, within the pipe 6 or at another place in the conduit leading thereinto, there may be provided a device which is adapted to vary the liquid inflow or to close off said inflow completely, e.g. a valve 12.

In order to be able particularly well to control the formation of foam and to control the way in which the foam passes onto the surface to be treated, and also for adjusting the time during which the foam acts on the material to be cleaned, the head 1 has behind the foaming means 3, 6 (when looking in the direction of withdrawal) arranged therein a wall 9 which similar to a gate may be raised or lowered at will whereby a withdrawal passage is created which extends over the entire width of the slot 4 and may be varied as to cross section.

The porous body 5 can selectively be Withdrawn from the range of the air passage or slot, for instance by turning or withdrawing its guiding means so that the air for the drying process can pass into the bell chamber for the 4 drying operation without being impeded in any way (see dot-dash line position 11 of body 5).

It is, of course, to be understood that the present invention is, by no means, limited to the method and apparatus set forth above but also comprises any modifications that will appear to those skilled in the art.

What is claimed is:

1. A method of treating textile floor covering, especially carpeting, with a fluid which includes the steps of: subjecting the treatment fluid for treating the textile floor covering to be treated to an underpressure preliminarily so as to produce a foam more effectively from said fluid, creating the underpressure primarily by a suction flow of air exerting a suction upon the foam where it is being formed permeable through porous passage, controlling said foam by varying said suction flow, and only subsequently applying the thus created foam to said textile floor covering.

2. A method according to claim 1, in which the foam subsequently applied to treat said textile floor covering is also withdrawn supplementary from said floor covering by the concurrent effect preliminarily of said underpressure.

3. A method according to claim 1, which includes the step of already warming up the treatment fluid prior to the more effective and stabilized formation of foam therefrom.

4. A method of treating textile floor covering, especially carpeting, with a fluid which includes the steps of: subjecting the treatment fluid for treating the textile floor covering to be treated to an underpressure preliminary so as to produce a foam more effectively from said fluid, already intermixing the treatment fluid with air under pressure particularly at the place of formation of the foam before floor application, and only subsequently applying the thus created foam to said textile floor covering.

5. A method of treating textile floor covering, especially carpeting, with a fluid which includes the steps of: subjecting the treatment fluid for treating the textile floor covering to be treated to an underpressure so as to produce a foam from said fluid, intermixing the treatment fluid with warmed up air under pressure at the place of formation of the foam, and applying the thus created foam to said textile floor covering.

6. A method of treating textile floor covering, especially carpeting, with a fluid which includes the steps of: subjecting the treatment fluid for treating the textile floor covering to be treated to an underpressure so as to produce a foam from said fluid and applying the thus created foam to said textile floor covering, following the application of a desired quantity of foam to the textile floor covering to be treated cutting off the supply of further treatment fluid and drying the wet textile floor covering by warm air conveyed to the place of formation of said foam.

References Cited UNITED STATES PATENTS 930,628 8/1909 Squier 15-322 X 1,498,255 6/1929 Winchester 15-320 1,929,345 10/1933 Brown et al. 15-321 2,292,435 8/1942 Critcs 15-321 WILLIAM I. PRICE, Primary Examiner US. Cl. X.R. 

